This application incorporates by reference of Taiwan application Serial No. 90205276, filed Apr. 4, 2001.
1. Field of the Invention
The invention relates in general to a hinge apparatus, and more particularly to a magnetic hinge apparatus.
2. Description of the Related Art
The trend of the portable device such as cellular phone is leaded towards the lighter, the thinner, and the smaller. Each component of the portable device has to be miniaturized. For example, cellular phone, the most popular portable product, has been through the great revolution in appearance design. Conventionally, the button portion of cellular phone is uncovered, and then a cover is added to protect the buttons from careless touch. The present cellular phone is further designed to be folded up for easy to carry. The exterior of cellular phone is lighter and handier. As a folding cellular phone presents, the display and the buttons are respectively equipped on the lid and body portion, and connected by a hinge apparatus. Hence, the folding cellular phone has an open position in the communication, and a close position at rest. The volume of cellular phone is greatly reduced due to its foldability. In the present cellular phone, a spring is mostly adopted of the hinge apparatus for providing a torsion force.
Referring to FIG. 1A, which shows the components of a conventional spring type hinge apparatus. The spring type hinge apparatus 100 includes a flanged shaft 102, a first cam 104, a second cam 106, and a spring 108. The first cam 104 has a convex portion 114 and a concave portion (not shown) in the profile. Also, the second cam 106 has a convex portion 116 and a concave portion 126 in the profile.
FIG. 1B is a perspective view of the assembled spring type hinge apparatus according to 1A. When assembling the spring type hinge apparatus, the flanged shaft 102 is inserted through the first cam 104, the second cam 106, and the spring 108. The convex portion 114 and the concave portion (not shown) of the first cam 104 are engaged with the concave portion 126 and the convex portion 116 of the second cam 106, respectively. It is noted that the elastic force from the compressed spring 108 pushes the second cam 106 towards the first cam 104 since the spring 108 coupled to the flanged shaft 102 resists one end of the second cam 106. Therefore, the first cam 104 and the second cam 106 are tightly engaged.
In the practical application, the spring type hinge apparatus 100 can be installed in any device having a cover (lid) and a base, to make the device semi-automatically open and close. For example, the spring type hinge apparatus 100, situated in the cellular phone for connecting the cover and the base, allows the pivoting of the cover on the base. In one practical case, the first cam 104 is fixed to the base while the second cam 106 is fixed to the cover. When the cellular phone is closed, the convex portion 114 and the concave portion of the first cam 104 are engaged with the concave portion 126 and the convex portion 116 of the second cam 106, respectively. When the cover of cellular phone is opened, the second cam 106 is simultaneously rotated with the cover so as to separate from the first cam 104.
It is noted that the second cam 106 is movably engaged on the flanged shaft 102. When the second cam 106 is rotated with the cover, the convex portion 116 is apart from the concave portion of the first cam 104, and then moves along the profile of the first cam 104 towards the convex portion 114; therefore, the second cam 106 is moved outward along the flanged shaft 102, and the spring 108 is compressed consequently. When the cover is opened to a specific angle that the convex portion 116 of the second cam 106 is against the convex portion 114 of the first cam 104, the maximum compression of the spring 108 is achieved. If the cover keeps on opening, the convex portion 116 of the second cam 106 is going to move across the convex portion 114 of the first cam 104, and the recovery force released from the spring 108 will push the second cam 106; thus, the second cam 106 moved inward along the flanged shaft 102 until the convex portion 116 of the second cam 106 engaged with another concave portion of the first cam. After both cams engage tightly again, the cellular phone is in full-opened condition. Similarly, the hinge action during the close condition is performed in reverse order.
Referring to FIG. 2, which shows operation of the conventional spring type hinge apparatus equipped in a folding cellular phone. The spring type hinge apparatus 100 pivotally connects the cover 200 and the base 202 of a folding cellular phone. The first cam 104 is connected to the base 202, and the second cam 106 is connected to the cover 200. In FIG. 2, the X-coordinate represents the rotating angle between the first cam 104 and the second cam 106. The Y-coordinate represents the position of the second cam 106 on the flanged shaft 102. When the opening angle of the folding cellular phone is 0xc2x0, the first cam 104 and the second cam 106 are tightly engaged to each other, and the second cam 106 is located on the flanged shaft 102 at position a.
When user keeps opening the cellular phone until the angle xc3xa1, the convex portion 116 of the second cam 106 is apart from the concave portion of the first cam 104, and consequently the second cam 106 moves outward (away from the first cam 104) along the flanged shaft 102 to position b. Meanwhile, as spring 108 is compressed, the elastic recovery force will push the second cam 106 to move the first cam 104 inward when the external force is removed.
When the cellular phone is opened to the angle xc3xa2, the convex portion 116 of the second cam 106 touches the convex portion 114 of the first cam 104. Meanwhile, the second cam 106 slides along the flanged shaft 102 to position c, and the compression of the spring 108 has reached its maximum. Consequently, an elastic recovery force is generated in converse direction. According to the foregoing illustration, it is required an external force to overcome the elastic recovery force while the opening angle has switched from 0xc2x0 to xc3xa2.
When the opening force to the cover 200 is continued and the opening angle is xc3xa3, the convex portion 116 of the second cam 106 is separated from the convex portion 114 of the first cam 104, and moves towards the other concave portion of the first cam 104. Simultaneously, the second cam 106 is propelled by the elastic recovery force generated from the compressed spring 108, and moves close to the first cam 104. Therefore, the cover is automatically flipped up without applying any external force.
When the cellular phone is full-opened (the opening angle is 180xc2x0), the convex portion 116 of the second cam 106 engages with the concave portion of the first cam 104, and the second cam 106 on the flanged shaft 102 is back to position a. In the meanwhile, the elastic recovery force of the spring 108 is completely released and recovers to the original uncompressed state.
The foregoing paragraphs clearly describe the operation of spring type hinge apparatus 100. Also, it is known that the open-close situation of cellular phone (180xc2x0xcx9c0xc2x0) with the reference of FIG. 2.
Generally, when the cellular phone is opened from the closed position to the angle xc3xa2, an external force is required to open the cover 200. In the meanwhile, the second cam 106 and the first cam 104 have approached the unstable state and attain the critical situation (which the convex portions are against to each other). Also, the spring 108 is compressed to the shortest condition. When the cellular phone keeps opening from the angle xc3xa2 to the full-opened position, the compressed spring 108 releases the elastic recovery force and pushes the second cam 106 to engage the first cam 104. Accordingly, the cellular phone equipped with the spring type hinge apparatus 100 possesses snap characteristic, wherein the cover in a certain angle is snapped into the full-opened position (ranged from xc3xa2 to 180xc2x0) or snapped into the closed position (ranged from xc3xa2 to 0xc2x0), without applying any external force.
However, the conventional spring type hinge apparatus 100 will loss the property of returning to the initial state following deformation after frequent usage. Also, it requires more space to install the spring type hinge apparatus 100 since the spring 108 occupies certain room. This increases the overall size of applied product.
It is therefore an object of the invention to provide a magnetic hinge apparatus to substitute the elastic force of conventional spring by the principle of magnetism. Because the like poles repel each other and the unlike poles attract each other, the product secured by the magnetic hinge apparatus of the invention possesses the snapping characteristic.
The invention achieves the above-identified objects by providing a magnetic hinge apparatus for connecting the cover and the base of the foldable product. The magnetic hinge apparatus comprises a shaft, the first, second, and third magnetic cams. In the practical application, the first magnetic cam connected to the base can be arranged on one end of the shaft, while the other end of the shaft is installed with the third magnetic cam. The second magnetic cam connected to the cover can be aligned between the first and the third magnetic cams. Both the second and third cams are connected to the cover. What the point of the invention is either the attractive force existing in the opposite profiles of the first magnetic cam and the second magnetic cam, or the repulsion force existing in the opposite profiles of the second magnetic cam and the third magnetic cam, or a combination thereof. The principle of magnetism makes the first magnetic cam and the second magnetic cam engage spontaneously.
Moreover, both opposite profiles of the first magnetic cam and the second magnetic cam have a convex portion and a convex portion. When the foldable product is full-closed, the convex portion of the second magnetic cam engages the concave portion of the first magnetic cam. When the cover of applied product is opened by an external force, the convex portion of the second magnetic cam is separated from the concave portion of the first magnetic cam, and slides on the profile of the first magnetic cam; meanwhile, the second magnetic cam moves toward the third magnetic cam. When the cover keeps opening and both concave portions of the first magnetic cam and the second magnetic cam touch each other, both cams are in the unsteady state. If the cover keeps opening, both concave portions of the first magnetic cam and the second magnetic cam will be separated; meanwhile, the attractive force (between the first magnetic cam and the second magnetic cam) and repulsion force (between the second magnetic cam and the third magnetic cam) are going to push the second magnetic cam. Under this condition, even the applying external force disappears, the second magnetic cam will spontaneously move towards the first magnetic until complete engagement is achieved. As a result, the cover is automatically opened to the full-opened state. Similarly, the magnetic hinge apparatus works in reverse order while the cover is rotated from the full-opened position to full-closed position. Accordingly, the foldable product secured by the magnetic hinge apparatus possesses snap characteristic.
Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.